It has been demonstrated that Duchenne's muscular dystrophy is caused by a mutation or deletion which results in the absence of the dystrophin protein. In addition, the nucleic acid sequence encoding the dystrophin protein has been isolated and the nucleotide sequence has been determined. These discoveries have enabled new diagnostic and therapeutic approaches to Duchenne's muscular dystrophy based on recombinant DNA technology.
Dystrophin has been shown to be associated with a large oligomeric complex of sarcolemmal glycoproteins (see, e.g., Ervasti and Campbell, Cell 66: 1121-1131 (1991)). Substantial reduction in selected components of the dystrophin-glycoprotein complex have also been found to correlate with disease phenotypes. The isolation and characterization of DNA encoding the various non-dystrophin components of the dystrophin-glycoprotein complex would enable diagnostic and therapeutic approaches similar to those discussed above in connection with the DNA encoding dystrophin.